Call indicator



Dec., 3, .1940. H. R. WARNKE CALL INDICATOR Filed July 5, 1959 2Sheets-Sheet l- Dec., 3, 1940. H. R. WARNKE 2,223,927

CALL INDICATOR Filed July 5, 1939 2 sheets-sheet 2 'MI/II Patented Dec.3, 1940 UNITED STATES CALL INDICATOR Herbert R. Warnke, East Orange, J.,assignor to vUnited States Instrument Corporation, East Grange, N. J., acorporation of New Jersey Application July 5, 1939, Serial No. 282,869

11 Claims.

This invention relates to call indicators or annunciators of the visualtype, for general use in suitable applications and, in particular,useful in connection with telephone systems of the direct connectedtype, i. e., in which no central switchboard is employed, the severalstations being directly connected to one another, or to a masterstation. The invention has for its general object the provision of meansfor visibly indicating the receipt of incoming calls, whereby if a callis received at a given station while the instrument at that station isin use, the call will nevertheless be registered by means o-f a visiblesignal which indicates the source of the call, so that the called l5partymay return the call after completing the current conversation.

An important feature of the present invention is that the indicator willregister all calls received, so that if a party is absent from hisstation, and

out of hearing of the usual audible signal, he will nevertheless beapprised, upon hisreturn, not only of the fact that he has been called,but of the identity of the calling station or stations.

Another object of the present invention is the provision Aof a visualindicator of the kind described, of novel and compact construction,incorporated in the base of a telephone instrument, whereby thenecessity of employing an annunciator of the cumbersome and expensivewall or fm desk type is obviated. A further object is the provision ofsuch an indicator in association with the usual station selector switch,in such a manner that the indicator signal is cancelled when theselector switch is moved to establish a talking circuit between thecalled station and the calling station.l

vAnother object is the provision of a visual indicator of the kinddescribed, said indicator being normally in series with the usualaudible signal, together with means whereby a shunt circuit isestablished through the visual indicator when `the instrument is in use.so that incoming calls will be registered although the audible signalwill remain silent.

Other and further objects, features and advantages of the presentinvention will be apparent to one skilled in the art from the followingdescription taken in connection with the accompanying drawings in which:

Figure 1 is a front elevation of a telephone instrument embodying thepresent invention;

Figure 2 is a front elevation of the selector switch and call indicatormechanism;

Figure 3 is a side elevation of the mechanism of Figure 2;

Figure 4 is a rear elevation of the mechanism of Figure 2; i

Figure 5 is a vertical section on line 5-5 of Figure 2;

Figure 6 is a fragmentary section on line 6-6 of Figure 5;

Figure rI-is an enlarged vertical section corresponding to the upperportion of Figure 5; and

Figure 8 is a circuit diagram illustrating one mode of employing thepresent invention in a telephone system. f

In order to facilitate an understanding of the invention, reference ismade to the embodiment thereof shown in the accompanying drawings anddetailed descriptive language is employed. It will nevertheless beunderstood that no limitation of the invention is thereby intended andthat various changes and `alterations are contemplated such as wouldordinarily occur to one skilled in the art tofwhich the inventionrelates.

In the present instance, the invention will be described as-embodied ina direct connected telephone system ofthe so-called master station type,in which one station, designated the master station, is connected witheach of a plu,- rality of subsidiary stations, the subsidiary stationsnot being connected to one another. In such a system, each subsidiarystation may only call the master station, but the latter may call eachof the subsidiary stations. In such a system, the call indicator of thepresent invention need only beinoorporated in the instrument at themaster station. However, it will be understood that the call indicatorof the present invention is capable of many and varied applications, andis' not limited to use in connection with a master station system.

Referring to the drawings, Figure 1 illustrates a telephone instrumentat the master station, comprising a base portion III and a hand set II.The details of the instruments (receiver and transmitter) within thehand set form no part of the present invention, and will not bedescribed herein. The base portion I 0 is provided with a dial plate I2numbered (in the illustrated embodiment) from l to 6, for cooperationwith the pointer I3 of a station selector switch to be hereinafterdescribed. Adjacent each numbered point on the dial plate I2, the casingwall of the instrument base is apertured to provide windows I4.Centrally of the dial plate I2, as best seen in Figure 3, the casingwall is tapped to receive a threaded bushing I5 in which is rotatablymounted the shaft I6 of the selector switch. The shaft I6 extendsrearwardly through an aperture I1 in a base plate I8, which latter isprovided with a rearwardly extending annular ange I9 defining a well 2U.A cam 2I is disposed within the well 2E) and is secured upon therearward end of the shaft I6 by means of a screw 22.

The selector switch comprises a` front plate 23 and a disc 24 ofinsulating material, spaced from the base plate I8 and from each otherby bolts 25 and sleeves 25. The insulating disc 24 carries a series ofcontact points adapted to be selectively engaged by a rotating contactmember, the contact points and rotating contact member being connectedin the circuit as illustrated diagrammatically in Figure 8. The detailsof the selector switch form no part of the present invention, and neednot be further described herein, but by way of explanation it may benoted that a suitable type of selector switch is described andillustrated in United States Patent No. 2,012,492.

A series of indicator arms 21, one for each window I4, are pivoted aboutthe periphery of the base plate IBI Each arm 21 comprises a rearwardportion 28 normally disposed parallel to the shaft I5 of the selector,an inwardly and forwardly extending portion 29, and a radially extendingflag portion 30 adapted to move behind one of the windows I4. The outerend of the forward surface of each ag portion 30, being normallydisposed behind a window I4, is preferably colored like the casing ofthe instrument base Ill, while the inner end of the same surface iscoated with material of a contrasting color, so that it may be readilydiscerned when an arm 21 has moved so as to bring the inner end of thenag 3l] opposite a window I4.

The indicator arms 21 are, constantly urged so as to cause the flagportions 30 to move outwardly, by means of small springs 3| (Figures 6and 7), but are normally maintained in the position illustrated by meansof latch members 32. Each latch member 32 is loosely mounted on a rod 33whichextends between the base plate I8 and a backing plate 34, whichlatter is secured to the rearward edge of the lilange I9 by means ofscrews 35. Each latch 32 is enabled to pivot rearwardly, being guidedtoprevent rotation by a pin 35 mounted in the base plate I8 andextending through a suitable aperture in the' latch member. The latchmembers are normally urged forwardly against the rear face of the baseplate by means of springs 31 surrounding the rods 33. A plate 38 ofinsulating material isgdisposed rearwardly of the backing plate 34,being secured in place by the screws 35.

A small electromagnet 39 is secured to the forward surface of thebacking plate 34 adjacent each latch member 32, the magnetsbeingconnected in the circuit as diagrammatically illustrated in Figure 8.The latch members 32 are formed of magnetic material, for example iron,and it will be readily apparent that when a magnet 39 is energized, thecorresponding latch member 32 will be attracted, disengaging it from thecorresponding arm 21 and permitting the latter to pivot in response tothe tension of its associated spring 3l. By this movemenuthe nag por-'tion of the arm 21 is moved outwardly with respect to the shaft I6,bringing the inner, contrastingly colored portionof the flag memberopposite the correspon-ding window I4 and indicating that a call hasbeen received from the corresponding subsidiary station.

Adjacent each indicator arm 21 there is provided a push rod 40 (Figure'6), which extends through a radial aperture in the base plate I8 andinto the well 2U adjacent the cam 2 I. The latter is provided with twoadjacent peripheral protuberances 4I, so arranged that the Valleybetween them occupies the same circumferential relationship to the shaftI@ as do the pointer I3 and the rotary switch arm of the selectorswitch. When the latter is turned to the dial position corresponding tothe calling station, so as to complete a talking circuit between thecalling station and the called station, one or another of theprotuberances 4I, depending upon the direction of movement, will engagethe inner end of the push rod lll and force the latter outwardly intoengagement with the portion 28 of the corresponding indicator arm 21,moving the latter outwardly against the tension of the spring 3|. Whenthis occurs, the latch member 32 is permitted to pivot forwardly underthe pressure of the spring 31, and again engages beneath the edge of therearward end of the arm 21, it being understood that the magnet 39 isnow de-energized. If the call is received when the pointer I3 happens tobe in a position corresponding to the calling station, the correspondingindicator arm Will move as above described, the push rod 40 engaging thecam 2l in the valley between the two protuberances 4I, as illustrated inFigure 6. In this case, the indicator may be reset at the conclusion ofthe call by moving the pointer I3 and cam 2| in either direction.

The call indicator of the present invention is applied in a masterstation system in the following manner: In Figure 8 there is illustrateda system adapted for a master station, shown in the center of thefigure, and six subsidiary stations, only two of the latter bein-gshown, however. The junction box 50, illustrated diagrammatically,furnishes a convenient mode of connecting the various subsidiary stationcircuits to the master station. The magnets 39 of the call indicator areshown adjacent the selector switch dial I2, and a buzzer or otheraudiblesignal is represented at 5I The latter is shunted by a 5 or 10 ohmresistance 5I', in order to pass sucient current to operate the visualcall indicatori It will be understood that the magnets, selector switch,and audible signal are all preferably arranged within an instrumentbase, such as the base I0 of Figure 1, which also carries plungers 52and 53, which are urged upwardly by spring contact arms 54 and 55,respectively, but are normally held in a depressed position by the handset I I', which rests upon the instrument base when not in use.

The telephone instruments inthe handsets II may be of the voice-poweredtype, requiringno external energy source, or of any suitable type. Inthe present case it is assumed that the voicepowered instruments areused, and no source of electrical energy is shown except the battery 55which furnishes energy for operating the visible and audible callsignals.

In addition to the contact arms 54 and 55,` each instrument base carriesspring Contact arms 51 and 53, adapted `to cooperate with the arms 54and 55, respectively, and contact arms 59 and Sil, adapted to cooperatewith each other. A strip of insulation 6l separates contact arms 55' and6D. In addition, the master station base carries a contact arm 62 whichis engaged by the arm 54 when the hand set is raised. In Figure 8, theseveral plungers 52 and 53 are shown in normal position, i. e., theposition which they occupy when the instrument is not in use. It will benoted that stations Nos. 1 and 2 are each connected by four bernfor'actuating the same to give a visible sig- Assuming, now, thatstation No.1, on the left, desires tov call the master station, the handset is lifted, allowing plungers 52 and 53 to4 rise. Plunger 52, whichmay be called the ringing button, is then depressed closing a circuitthrough contact arm 54, conductor 63, junction box 50, conductor 64,battery 56, conductors 65 and 66, in parallel through the buzzer 5| andresistance 5I', through conductor 61, contact arms 6D and 59, conductors6B, 69, the left hand magnet 39, conductor 10, junction box 50,' vandconductor 1I back to contact arm 51. Thus the buzzer 5I and visualindicator will both be actuated. If now the party at the master stationlifts the hand set and turns the selector switch to station No. 1 on thedial, the visual indicator is reset as previously described,` and atalking circuit is established from the hand set I I of station No. 1through conductors 12, 13, junction box 50, conductor 14, the switch armof the selector switch (corresponding to pointer I3) conductor 15,through the hand set II of the master station, conductor 16, contactarms 58, 55, conductor 11, junction box 55, conductor 18, contact arms55 and 58 of station No. 1, and conductor 19 back to hand set II ofstation No, 1.

If the master station is talking to another subsidiary station whenstation No.1 calls, the circuit through buzzer 5I will be open, byreason of contact arms 59 and 60 being separated, but a circuit will becompleted through the visual call indicator by means .of conductor 8E),contact arms 54 and 62, which are now in engagement, and conductor 8l.Thus the buzzer will not sound, but the visual indicator will beactuated.

When the master station desires to call a subsidiary station, thepointer I3 is positioned accordingly, the hand set lifted, and theplunger 52 at the master station is depressed. It is believedunnecessary to trace the resulting circuit, except to point out that thecircuit includes the contact arms 59 and 50 at the subsidiary station.

en the hand set at the latter station is lifted, the contact arms 59 and60 separate and contact arms 55 and 58 engage, closing the talkingcircuit.

One important advantage of the present invention, in connection withmaster station systems, is that it is unnecessary to employ code ringingto apprise the master station of the identity of the calling station,which is ordinarily the case in order that the selector switch may becorrectly operated to close the talking circuit.

While the present invention is primarily intended for telephone use, itobviously will be useful in other applications, as in elevator callsystems and many other types of electrical signalling systems.

Having thus described the invention, what is claimed as new and desiredto be secured by. Letters Patent is:

1. In a telephone system of the direct connected type, a plurality oftelephone instruments at different stations, electrical conductorsconnecting said instruments, `a station selector switch at one of saidstations for selectively connecting the instrument at said station withsaid other instruments, and a call indicator associated with saidselector switch, said call indicator comprising a plurality of movablemembers corresponding to the other stations in said system,electromagnetic means associated with each said movable memwires to themaster station, but are not'connected nal, each said electromagneticmeans being in circuit with one of said other stations, and meansassociated with said selector switch for resetting said movable membersto normal position when the corresponding stations are selected.

2. In a system according to claim 1, an audible signal device at4 `saidstation and normally in series with f said electromagnetic means, andmeans for shunting said audible signal device when the instrument atsaid station is in use.

3. In a telephone system of the direct connected type, a plurality oftelephone instruments at different stations, electrical conductorsconnecting said instruments, 'a station selector switch at one of saidstations for selectively connecting the instrument at saidA station withsaid other instruments, and a call indicator associated with saidselector switch, said call indicator comprising a plurality of movablemembers corresponding to the other stations in said system, latch meansassociated with each movable memberfor maintaining it in normalposition, means urging each said member to indicating position,electromagnetic means associated with each said member and adapted whenenergized to actuate said latch means lto release said member, each saidelectromagnetic means being in circuit with one of said other stations,and means associated with said selector switch for resetting saidmembers and latch means when the corresponding stations are selected.

4. In a telephone system of the direct connected type, a plurality oftelephone instruments at different stations, electrical conductors con-I necting .said instruments, a station selector switch at one of saidstations for selectively conresponding to the other stations in saidsystem,

electromagnetic means associated with each said movable member foractuating the same to give a visible signal, each said electromagneticmeans being in circuit with one of said other stations, and meansassociated with said selector switch for resetting said movable membersto normal position when the corresponding stations are selected, saidlast means comprising a cam rotatable with said selector switch andmeans associated with each said movable member and adapted to projectinto the path of said cam when said member is in indicating position.

5. In Ia telephone system having a plurality of stations, a telephoneinstrument at one of said stations comprising a casing, a selectorswitch mounted in a wall of said casing, a plurality of numbered windowsin said casing wall and surrounding said selector switch, said windowscorresponding to the other stations in said system, a movable memberarranged inside said casing adjacent each said Window, means associatedwith each said movable member for causing it to give a signal which isvisible in its associated window whenever a call is received from thecorresponding station, and means associated with said selector switchfor resetting said movable members.

6. In a telephone system having a plurality of stations, a telephoneinstrument at one of said stations comprising a casing, a selectorswitch mounted in a wall of said casing, movable members arrangedadjacent said selector switch and corresponding respectively to theother stations in said system, means for moving each said mem-l sition,said last means comprising a cam rotatable with said selector switch andmeans associated with each said movable member and adapted to projectinto the path of said cam when said member is in indicating position.

8. In a telephone system having a plurality of stations, a telephoneinstrument at one of said stations comprising a casing, a selectorswitch mounted in a wall of said casing, a plurality of numbered windowsin said casing wall and surrounding said selector switch, said windowscorresponding to the other stations in said system, a movable memberarranged inside said casing adjacent each said window, means associatedwith each said movable member for causing it to give a signal which isVisible in its associated window whenever a call is received from thecorresponding station, and means associated with said selector switchfor resetting said movable members, said last means comprising a cam Lrotatable with said selector switch and means associated with each saidmovable member and adapted to project into the path of said cam whensaid member is in indicating position.

9. In a telephone system comprising a master station and a plurality ofother stations directly connected to s aid master station, a stationselector switch at said master station for selectively connecting theinstrument at said station with said other instruments, and a callindicator associated with said selector switch, said call indicatorcomprising a plurality oi movable members corresponding to the otherstations in said system, electromagnetic means associated with each saidmovable member for actuating the same to give a visible signal, eachsaid electromagnetic means being in Acircuit with one of said otherstations, and means associated with said selector switch for resettingsaid movable members to normal position when the corresponding stationsare selected.

10. A call indicator comprising a plurality of movable members eachhaving a flag portion, latch means associated with each movable memberfor maintaining it in normal position, means urging each said member toindicating position, electromagnetic means associated with each saidmember and adapted when energized to actuate said latch means to releasesaid member, means for selectively energizing said electromagneticmeans, and means for resetting said movable members.

11. A call indicator according to claim l0, said last means comprising amovable cam for resetting said movable members and a pointer movablewith said cam and cooperatively associated with said movable members toindicate the position of the cam relative thereto.

HERBERT R. WARNKE.

